U.S. Pat. No. 4,551,986, which is assigned to the same assignee as the present application, discloses a transport refrigeration system for mounting on the nose of a trailer, between a trailer and the associated tractor or cab. The refrigeration system disclosed in the aforesaid patent has a depth dimension measured in a horizontal longitudinal direction between a tractor and associated trailer of about 30 to 32 inches (762-812 mm.). This locates the housing or unit cover within a 62 inch (1575 mm.) swing radius on a 36 inch (914 mm.) trailer king pin location, which is suitable for the North American market, providing approximately 12.75 square feet (1.184 square meters) of top view area for the refrigeration system.
New regulations in the European Economic Community (EEC) require transport refrigeration systems which are nose mounted on a highway trailer to be within a 2040 mm. swing radius, from a kingpin location of 12 meters from the rear of the trailer. These requirements dictate a depth dimension for a transport refrigeration unit of 21 inches (533 mm.), or less. This provides only 7.86 square feet top view area (0.73 square meter) of space for the transport refrigeration unit, a 39% reduction from the North American design configuration. This shallow depth dimension must be achieved with a "zero cube" evaporator, ie., without penetration of the evaporator into the payload area of the trailer.
It would be desirable, and it is an object of the present invention, to provide a transport refrigeration unit having a component layout and configuration which enables the unit to meet the EEC space requirement, without a corresponding loss in performance, i.e., refrigeration capacity.